Stem cell–nanomedicine system as a theranostic bio-gadolinium agent for targeted neutron capture cancer therapy

The potential clinical application of gadolinium-neutron capture therapy (Gd-NCT) for glioblastoma multiforme (GBM) treatment has been compromised by the fast clearance and nonspecific biodistribution of gadolinium-based agents. We have developed a stem cell–nanoparticle system (SNS) to actively target GBM for advanced Gd-NCT by magnetizing umbilical cord mesenchymal stem cells (UMSCs) using gadodiamide-concealed magnetic nanoparticles (Gd-FPFNP). Nanoformulated gadodiamide shielded by a dense surface composed of fucoidan and polyvinyl alcohol demonstrates enhanced cellular association and biocompatibility in UMSCs. The SNS preserves the ability of UMSCs to actively penetrate the blood brain barrier and home to GBM and, when magnetically navigates by an external magnetic field, an 8-fold increase in tumor-to-blood ratio is achieved compared with clinical data. In an orthotopic GBM-bearing rat model, using a single dose of irradiation and an ultra-low gadolinium dose (200 μg kg−1), SNS significantly attenuates GBM progression without inducing safety issues, prolonging median survival 2.5-fold compared to free gadodiamide. The SNS is a cell-based delivery system that integrates the strengths of cell therapy and nanotechnology, which provides an alternative strategy for the treatment of brain diseases.


Reporting for specific materials, systems and methods
We require information from authors about some types of materials, experimental systems and methods used in many studies. Here, indicate whether each material, system or method listed is relevant to your study. If you are not sure if a list item applies to your research, read the appropriate section before selecting a response. Validation Sample sizes were based on previous experience and publications. We preformed sample size calculations on online platform-EDA (Experimental Design Assistant, national centre for the replacement refinement & reduction of animals in research, https://eda.nc3rs.org.uk/ about).
[1] Following the instructions of EDA, we finished the experiment design diagram and typed the certain parameters which were based on results from published studies for power analysis. This was determined at a minimum of 5 rats for each group. In general, 6-8 rats or 3-4 samples per group are appropriate for in vivo experiments involving therapeutic efficacy, survival, and flow cytometry. 1. Towner RA, et al. Regression of glioma tumor growth in F98 and U87 rat glioma models by the Nitrone OKN-007. Neuro-oncology 15, 330-340 (2013). 330-340 (2013).
No data was excluded.
As reported in Methods Section, experiments were all replicated at at least three times (n = 3 rats, mice or cell samples cultured in independent space such as plate or disk), and attempts at replication were successful.
All animals were randomized between groups.
Animals were assigned randomly to control and experimental groups. Although experimenters were not blinded to group allocation for data collection, subsequent offline analysis was performed blinded to experimental conditions. The experimenters were blinded to experimental conditions for analysis of immunohistochemistry and in situ hybridization.
We did not detect contamination of the cells using Hoechst DNA stain method and agar culture method.
Not any misidentified line is used in this study.
The female rats strain F344/NNarl (RMRC21002) aged 8 weeks and the male mice strain C57BL/6JNarl (RMRC11005) aged 8 weeks both were purchased from National Laboratory Animal Center, Taipei, Taiwan.

March 2021
Wild animals

Field-collected samples
Ethics oversight Note that full information on the approval of the study protocol must also be provided in the manuscript.

Human research participants
Policy information about studies involving human research participants Population characteristics

Recruitment
Ethics oversight Note that full information on the approval of the study protocol must also be provided in the manuscript.

Flow Cytometry
Plots Confirm that: The axis labels state the marker and fluorochrome used (e.g. CD4-FITC).
The axis scales are clearly visible. Include numbers along axes only for bottom left plot of group (a 'group' is an analysis of identical markers).
All plots are contour plots with outliers or pseudocolor plots.
A numerical value for number of cells or percentage (with statistics) is provided. To collect umbilical cord mesenchymal stem cells, 30 pregnant women were designed to be included in the studies for the placenta donation. The inclusion criteria were (1) 34 weeks or longer pregnant with intact placenta, (2) free of complications of pregnancy, and (3) healthy pregnant women and fetus. The exclusion criteria were (1) with critical illness such as diabetes, immune-related diseases, or cancers, (2) asymptomatic hepatitis A,B or C carriers and syphilis patients, (3) being evaluated as an improper case by the doctor, (4) having or have even been diagnosed with pulmonary tuberculosis, and (5) tested positive with treponema pallidum, Chlamydia trachomatis, human T cell leukemia virus, West Nile Virus or Neisseria gonorrhea within 8 weeks prior to giving birth, and (6) ever being diagnosed withs Zika or HIV.

Methodology
Written informed consent was acquired from the pregnant women. The pregnant women who agree to donate the placenta and match the above characteristic were approached and recruited into the studies without any additional bias.
The gating strategies was performed based on the justification of first gate, exclusion of doublets by FSC-A and FSC-H, exclusion of dead cells by selection of 7-AAD-/CD90+ To evaluate the targeting ability and accumulation of SNS in GBM via the signal from gadodiamide and nano iron in Gd-FPFNP (In vivo). To evaluate the imaging ability of SNS (In vitro).
After injection of different groups as figure 4 listed, MRI was performed on F344 rats under anesthesia in a 3-Tesla (3-T)